Exposure method

Abstract

The invention provides an exposure method for manufacturing a device. The method includes providing a wafer having several exposure regions with a photoresist layer covering thereon. A feedback parameter map with several exposure-region feedback parameter sets respectively corresponds to the exposure regions of the wafer. At least one of the exposure-region feedback parameter sets is different from the rest of the exposure-region feedback parameter sets. According to the feedback parameter map, an exposure process is sequentially performed on each of the exposure regions of the wafer through an exposure tool to pattern the photoresist layer on the wafer. While the exposure tool performs the exposure process on each of the exposure regions, an exposure process parameter set of the exposure tool is adjusted based on the exposure-region feedback parameter sets corresponding to the exposure region in the feedback parameter map.

1. An exposure method for manufacturing a device to improve an overlay alignment of successive layers in the device, the exposure method comprising:
 providing a wafer, wherein the wafer is covered by a photoresist layer, and the wafer is divided into a plurality of exposure regions; 
 providing a feedback parameter map, wherein the feedback parameter map has a plurality of exposure-region feedback parameter sets respectively corresponding to the exposure regions of the wafer, and at least one of the exposure-region feedback parameter sets is different from the rest of the exposure-region feedback parameter sets, the feedback parameter map is obtained according to a device testing trend diagram, and the device testing trend diagram comprises a device threshold current trend diagram and a device leakage current trend diagram; and 
 performing an exposure process sequentially on each of the exposure regions on the wafer through an exposure tool to pattern the photoresist layer according to the feedback parameter map, wherein an exposure process parameter set of the exposure tool is adjusted based on the exposure-region feedback parameter sets corresponding to each of the exposure regions in the feedback parameter map while the exposure tool performs the exposure process on each of the exposure regions. 
 
     
     
       2. The exposure method according to  claim 1 , wherein the device testing trend diagram is obtained by steps as follows:
 providing a plurality of pilot-run wafers; 
 performing a pilot-run process of the device on each of the pilot-run wafers; 
 performing a wafer acceptable test (WAT) on each of the pilot-run wafers undergone the pilot-run process for generating a testing information corresponding to each of the pilot-run wafers; and 
 collecting the testing information to create the device testing trend diagram. 
 
     
     
       3. The exposure method according to  claim 2 , wherein the step of obtaining the feedback parameter map according to the device testing trend diagram comprises:
 providing an after-etching critical dimension information and an after-develop critical dimension information corresponding to the exposure process; and 
 correlating the device testing trend diagram with the after-etching critical dimension information and the after-develop critical dimension information respectively to obtain the feedback parameter map. 
 
     
     
       4. The exposure method according to  claim 1 , wherein the step for performing the exposure process on each of the exposure regions by using the exposure tool further comprises adjusting the exposure process parameter set of the exposure tool according to a wafer feedback parameter set fed back from an advance process control (APC). 
     
     
       5. The exposure method according to  claim 1 , wherein the exposure parameter set comprises an exposure dose, a light incident angle, an exposure focus and an overlay offset parameter set. 
     
     
       6. An exposure method adapted for manufacturing a device through a first tool path to improve an overlay alignment of successive layers in the device, the exposure method comprising:
 providing a wafer, wherein the wafer is covered by a photoresist layer, the wafer being divided into a plurality of exposure regions; 
 obtaining a first feedback parameter map from a database according to the first tool path, wherein the first feedback parameter map has a plurality of exposure-region feedback parameter sets respectively corresponding to the exposure regions of the wafer, at least one of the exposure-region feedback parameter sets being different from the rest of the exposure-region feedback parameter sets, the first feedback parameter map is obtained according to a device testing trend diagram, and the device testing trend diagram comprises a device threshold current trend diagram and a device leakage current trend diagram; and 
 performing an exposure process on each of the exposure regions on the wafer through an exposure tool according to the first feedback parameter map to pattern the photoresist layer on the wafer, wherein an exposure process parameter set of the exposure tool is adjusted based on the exposure-region feedback parameter set corresponding to each of the exposure regions in the first feedback parameter map while the exposure tool performs the exposure process on each of the exposure regions. 
 
     
     
       7. The exposure method according to  claim 6 , wherein the database includes a plurality of data sheets, each of the data sheets being corresponding to a device manufacturing process, each of the data sheets storing a plurality of tool paths corresponding to the device manufacturing process and a plurality of feedback parameter maps respectively corresponding to the tool paths. 
     
     
       8. The exposure method according to  claim 7 , wherein the device testing trend diagram is obtained by steps as follows:
 providing a plurality of pilot-run wafers; 
 performing a pilot-run process on each of the pilot-run wafers through a tool path; 
 performing a WAT on each of the pilot-run wafers undergone the pilot-run process for generating a testing information corresponding to each of the pilot-run wafers; and 
 collecting the testing information to create the device testing trend diagram. 
 
     
     
       9. The exposure method according to  claim 8 , wherein the step of obtaining the first feedback parameter map according to the device testing trend diagram comprises:
 providing an after-etching critical dimension information and an after-develop critical dimension information corresponding to the exposure process; and 
 correlating the device testing trend diagram with the after-etching critical dimension information and the after-develop critical dimension information respectively to obtain the first feedback parameter map. 
 
     
     
       10. The exposure method according to  claim 6 , wherein the step for performing the exposure process on each of the exposure regions by using the exposure tool further comprises adjusting the exposure process parameter set of the exposure tool according to a wafer feedback parameter set fed back from an advance process control (APC). 
     
     
       11. The exposure method according to  claim 6 , wherein the exposure parameter set comprises an exposure dose, a light incident angle, an exposure focus and an overlay offset parameter set.